This invention relates to vehicle odometers and, more particularly, to a new and improved odometer operating on the Doppler principle.
Conventional vehicle odometers are subject to the disadvantage that their readings depend on various unavoidable influences, for example, wheel slip and variable transmission ratios due to differences in tire sizes and tire pressures. Furthermore, different types of vehicles require odometers of different designs.
The Published European Patent Application No. 0,003,606A2 mentions the possibility of using radar systems operating on the Doppler principle, such as are in conventional use for monitoring speeds in road traffic, for measurement of distance traveled by a vehicle, but it does not describe any particular system. An odometer device utilizing the Doppler principle, because it ascertains the distance traveled directly with respect to the ground, would have the advantage of eliminating the adverse influences mentioned above.